Load Testing Blog
Internet Explorer Static File Caching Defect
In going through cases we have with some customers, we’ve seen a few instances where Internet Explorer does not cache shared static resources. Within Load Tester, this problem becomes immediately apparent:
Note that the shared CSS, Javascript, and images are re-requested again on the About page and every other recorded page that uses them. Note also, these files don’t come back with a 304 (Not Modified), but instead the full content of the file is sent over and over again through a HTTP 200. Normally, the browser should load these files … Continue reading »
Load Tester 4.3 Improvements: Speculative Authentication for IE8 and IE9
Load Tester 4.3 carries a number of improvements for both ease of configuration, and accuracy of test simulation. Among these improvements comes support for speculative authentication, allowing Load Tester to simulate behavior from IE 9. The speculative authentication is only used for HTTP authentication schemes used by Load Tester’s Connection Negotiation Authentication feature. More information about HTTP authentication is available under How HTTP Authentication works and why load testers should care.
To describe the speculative authentication feature, … Continue reading »
What’s new in Load Tester 4.2
The 4.2 release focuses on platform compatibility and productivity increases from our services work in the past year with such clients as the US Census and the New York Marathon.
With a slew of new browsers and operating systems available, this release also includes support for 64-bit Windows and AIX operating systems, the latest versions of Internet Explorer, as well as the Chrome and Safari browsers.
On the productivity side there are some pretty big changes to allow testers to configure more complex testcases with less effort than ever before. Some of … Continue reading »
IE Performance Tip: avoid repeating <img> tags
This tip is more for those users who have developed a sophisticated data-crunching interface to their app. On one screen, for simplicity, the app gives a long list of data, without pagination controls being created by the user (such as a “View All” feature). To keep it pretty, each line has a visual icon or some surrounding images. Sound familiar? For example, let’s say the list is created by a testing system, indicating which tests were passed and which failed. The list may look something like:
For this example, we’ve … Continue reading »
IE8, favicon.ico and silly server stunts
At first glance, load testing software seems like it should be pretty straightforward. And like most things, it turns out to be really complex — at least, if you want to do it well. Simulating a browser could be pretty easy – except for the need to do it very, very, very efficiently, so that the solution can scale to simulate hundreds or thousands of virtual users per computer.
What does this have to do with favicon.ico and IE8? Occasionally while helping a customer use Load Tester, we run into some … Continue reading »
A Unique Browser approach to Fast: Opera Turbo
We’ve seen that modern browsers have made great strides to improve efficiency in rendering and javascript performance. But, the differences seem to be less noticeable when the network is stubborn. On a recent trip, I ran into just this problem. During the evening, the hotel’s local Wi-Fi seemed at peak capacity, the DNS servers were sluggish, and just getting connections opened often added a couple seconds. Getting onto common sites like Slashdot seemed to take 30 seconds or more from the overburdened local connection.
This seemed like a … Continue reading »
New JavaScript optimizer
From a load testing perspective, we are not generally concerned with Javascript performance – since it affects client-side rendering time and therefore has little relationship to load. However, we do see a lot of sites that could benefit greatly from improved Javascript performance – especially reducing the size of their Javascript files. Google has a relatively new project, Closure Compiler, that optimizes JavaScript code to reduce size and improve performance.
If you’ve tried the Closure Compiler, give us a shout. We’d love to hear about your results!
Chris
Chief Engineer
Load Testing with IE 8.0, Firefox 3.5
The performance improvements in the latest browsers (Internet Explorer 8.0 and Firefox 3.5) have been eagerly awaited for many months…though they come at a price.
Beta Browser Shootout
The latest crop of beta browsers, IE 8, Safari 4, and Google’s Chrome first release are examined using the most popular websites to see if any of them are indeed faster than the competition.
Read the article.
Memory consumption and reclamation – Chrome vs. Firefox
I reboot my laptop as infrequently as possible – which means that I keep Firefox running for weeks without restarting. At least, I would prefer to. But the longer it runs, the more memory it gobbles. The only way to reclaim it is to restart.
So when I read about the tab-isolation feature in Googles new Chrome browser which uses a separate process for each tab, it peaked my interest. I installed Chrome and tried a very quick (and not very scientific) test, as described below.
Firefox had been open … Continue reading »
